Flotation apparatus



A. c. DAMAN Dec. 18, 1934.

FLoTATIoN APPARATUS Filed Julylo, 1928 2 Sheets-Sheeil ARTHUR C. DAMAN Z7 I arrow,

DBC. 18, v A C' DAMAN FLOTATION APPARATUS Filed July 1o, 1928 2 sheets-sheet 2 i pf:

gwowytoz aucun ,estema ou. 18.11934 1,985,153

UNITE-D STATES PATENT AOFFICE Appliclartti-Jlynlzzsm, :231,583

9 chills. (Cl. 261-93) This invention relates to flotation machines Fig. 6 is a plan view of the impeller of Fig. 5. more particularly to the impeller and the arrang Fig. 'I is a cross section through a flotation cell ment of the impellers for flotation machines. illustrating a fourth form of the invention.

The usual flotation machine impeller is re- Fig. 8 is a plan view of the impellerof Fig. '1.

quired to raise the material into it by suction be- In lthe drawings the flotation cells are designat- `5 fore projecting it by centrifugal action. The size ed by the numeral 10 and the impeller shafts arof the material which can be handled in a maranged to vertically rotate therein are designated chine of this character is therefore, limited by the by the numeral 11. In the bottom of each cell size which can be successfully drawn upward by 10,. a bowl-shaped liner ,12 is placed to direct 10 the impeller. The principal object of this inventhe impeller currents upwardly into the cell. 10

tion is to provide an emcient impeller designed to In the rst form of my invention, illustrated in receive the material upon its upper surface by Figs. 1 and 3, the shaft 11 extends through a holthe action of gravity. The range of size of the low air-column 13 which extends above the soluparticles that can be handled byl this Aimproved tion line in the cell and terminates immediately 1'5 impeller is therefore substantially increased. over the impeller which is designated in its enl5 Another object of the invention is to provide a -tirety by the numeral 14. horizontally rotatingimpeller which will receive 'I'he feed .sleeve 13 is supported from a spider pulp by gravity and eject the pulp combined with 25 which rests upon the bowl 12. 'I'he impeller 14 air in intimate relation by centrifugal action. comprises a housing formed with a semi-conical i 2o A further object of the invention is to provide top plate 15 and a bottom disc 16.' The top plate 20 an impeller which will receive falling pulp at its and thedisc 16 are separated by impeller vanes upper side and air at its lower side and eject the 17. 'I'he impeller 14 is'secured to the shaft 11 by pulp and air, intimately mixed, at high velocity. means of a hub 18 within the housing, as shown A still further object of the invention is to proat 19, which forms an upper pulp passage 20 land vide an impeller which will be more eillcient in a lower air passage 21. The passages 20 and 21 25 operation than the usual open type impellers and are divided into a series of segment shaped paswhich will reduce the usual loss encountered by sages by the vanes 17, the outlets of which are at slippage or'over-riding of the pulp over the blades the periphery of the housing. of the impeller. The bottom disc 16 is opened. at its center as And a stili further objectof the invention is to shown at22 to receive an air supply pipe 23. The 30 so construct the impeller that itwill not become top 15 of the impeller rides in closeproximity to frozen or locked in position by settling sand in the lower edgevof the stationary lair column 13 case of a shut down. l and the end of the air supply pipe 23 is in close Other objects and advantages reside in the proximity to the bottom of the hub 1 9.

detail construction of the invention, which is de- In use the impeller is rapidly rotated and pulp 35 signed for simplicity, economy, and efficiency. is fed into the air-column 13 at a -point below the These will become more apparent from the folliquid level through a supply chute 24 or in any lowing description. desired manner. This pulp `falls upon the im- In the following detailed description of the inpeller, is sucked into the passages 20 and is disv 40 vention reference is had to the accompanying charged at the periphery by centrifugal action. 40 drawings which form a part hereof. Like nu- Simultaneously, air from'the column 23 will be merals refer to like parts in all views of the drawdrawn through the air passages 21 and discharged ings and throughout the description. into the discharging pulp. This construction In the drawings: provides a very intimate mixture of the pulp and Fig. 1 is a vertical section through a flotation air and results in an enlcient separation of the 45 machine cell such as -illustrated in my co-pending mineral and gangue. E v application, Serial No. 260,335, (Patent No. 1,942,- 1 In the second form of my invention, illustrated 803 dated Jan. 9, 1934) illustrating one form of in Figs. 2 and 4, the column 13 terminates at its my improved impeller in place therein. vlower extremity in a circular shield 27 immedi Fig. 2 is a similar cross section illustrating a ately above` 'an impeller 28- The impeller 28 50 second form ofthe impeller. comprises a bottom disc 29 supporting impeller Fig. 3 is a plan view ofthe impellerof Fig. 1. vanes 30 which carry an annular top plate 31. Fig. 4 is a pla'n view of the impeller of Fig. 2. Upon the bottom of the disc 29 relatively nar- Fig. 5 is a cross section through a flotation cell row blades 32 are carried.

illustrating a third form of the impeller. In operation of the second form, the lpulp falls 55 Impeller blades 36 project from the hub 35 and support an annular bottom plate 37. In this form of the invention the impeller is covered or protected by a cover plate 38 which is fixed to and supported on a feed sleeve 39.

In operation of the form of Fig. 5, pulp falls from the feed sleeve 39 between the blades 36 and upon the hub 35. This pulp is thrown outwardly by the rotation of the impeller and intimately mixed with air from an air feed pipe 40 which projects into the impeller through the bottom plate 37. The hub 35 is spaced from the bottom plate 37 to provide air passages 41.

In the fourth form of the invention as illustrated in Figs. 7 and 8, I employ an impeller somewhat similar to the impeller of Fig. 5, in that 'it has a bottom plate 42 supported on blades 43 from a disc-like hub 44. In this form, howf ever, the impeller is enclosed by an annular top plate 45 which rotates with the impeller immediately below the shield 27.

The action of this impeller is similar to the one of Fig. 5, but escape of the material over the tops of the blades is prevented by the top plate 45.

It is desired to be understood that the various features of the various forms may be combined, that is, the form of Fig. 1 could be provided with a stationary shield similar to the shield 38 of Fig. 5, if desired. Or the shields could be omitted from the impellers of Figs. 2, 5, and 7, without departing from the spirit of the invention. In the operation of the cell wear will occur by material passing between the end of theaircolumn and the impeller. This wear constantly increases the opening between the column and impeller and lessens the efficiency of the device. To accommodate for this wear, I provide -a `takeup device such as Aillustrated in Fig. 5, in which, the shaft 11 is supported on a step bearing 46 which can be raised or lowered by means of an adjusting screw 47 carried in an angle member 48 that supports the bearing 46. Thus as wear occurs between the blades and the shield the screw 47 can be tightened so as to raise the shaft 11 and bring the impeller into closer proximity with the column. v v

The shields over 'the impellers serve to prevent sand from settling into and around the impellerswhen the machine is shut down, thus requiring but a minimum of power tovagain place the machine in operation.

The air supply pipes 23, 33, and 40 can in some installations be dispensed with. In which event, the lower portions of the impellers will act to draw material from the cell or from a source outside the cell through a conductor 49, for recirculation. y

This conduit is of particular value in the retreatment of middlings or other products of the cell. Retreatment of material in the cell may be effected by openings 13a in the air-column, as shown in Figure 7, by which the material may be re-circulated thrdugh the impeller. y

While a specicI form of the improvement has nasales Y been described and illustrated herein, it is de-.,

sired to be understood that the same may be varied, within the scope of the appended claims,

without departing from the spirit of the invention.

Having thus described the invention, what I claim and desire secured by Letters Patent is:-

1. In iiotation apparatus, a flotation cell, an impeller element in the lower portion thereof, including a housing having an ingress opening and peripheral egress opening, a stationary conductive-element communicating directly with the ingress-opening and extending above a determinate liquid-level in the cell, for the admission of air to the impeller element, means for feeding material to the impeller element, and a shaft car-v rying. the impeller element, a bearing for said shaft, and adjusting mechanism apart from said vbearing so arranged that the operation thereof will cause a movement of 'the impeller element toward or away from said stationary element.

2. In flotation apparatus, a flotation cell, a rotary, vertically movable shaft, an impeller at the lower end of the shaft, within the otafion-cell, including a housing having an ingress-opening; and peripheral egress-openings, a stationary conductive-element communicating directly with the ingress-opening and extending above a determi..

nate liquid-level in the cell, for the admission of air to the impeller element, a shield at the lower end of the conductive-element covering the impeller-housing, around its ingress-opening, a shaft carrying theimpeller element, a bearing for said shaft, adjusting mechanism apart from said bearing so arranged that the operation thereof will cause a movement of the impeller element toward or away from said stationary element.

4. In flotation apparatus, a flotation cell, an impeller element in the lower portion thereof, including a housing having an upper ingressopening, a bottom-opening opposite thereto, and peripheral egress openings, a stationary conductive-element communicating directly with the ingress opening and extending above a determinate liquid level in the cell, for the admission of air to the impeller element, a conduit fdr the admission of a. gas under pressure to the impeller element through the bottom opening, and means for feeding material to. the impeller element.

5. In flotation apparatus, a notation cell, an impeller element in the lower portion thereof, in-

cluding a housing having an upper ingress-openY impeller element in the lower portion thereof, including a housing having upper and lower ingress-openings and peripheral egress-openings, a stationary conductive-element communicating with the upper ingress-opening and extending above a determinate liquid-level in the cell, for the admission of air and material to the impeller element, a conduit for the admission of gas under pressure to theimpeller element, and a stationary feed-pipe connected with the lower ingress-opening of the impeller element.

7. In otation apparatus, a flotation-cell, an

impeller element in the lower portion thereof, including a housing having upper and lower ingrass-openings and peripheral egress-openings, a stationary conductive-element communicating with the upper ingress-opening and extending above a determinate liquid-level in the cell, for the admission of air and material to the element, a stationary feed-pipe connected with the lower ingress-opening of the impeller element, and a pipe extending through the lower ingress opening for the supply of a gas under pressure to the" impeller element..v l

8. In iiotation apparatus, a flotation cell, an impeller element in the cell, a stationary conductive element communicating with the impeller element, a shaft carrying the impeller element, a bearing for said shaft, and adjusting mechanism apart from said bearing so arranged that the operation thereof will cause a movement of the impeller element toward or away from the stationary element.

9. In otation apparatus,'a flotation cell, a

rotary, vertically movable shaft, an impeller element at the lower end of the shaft, within the cell, a stationary conductive element communieating with the impeller element,- a bearing for the shaft outside the cell, and mechanism apart from said bearing so arranged that the operationA 

